package org.wangchaocheng.cloudgallery.common.utils;

import lombok.extern.slf4j.Slf4j;
import org.jetbrains.annotations.NotNull;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

/**
 * 通过SpringContextHolder获取bean对象的工具类
 *
 * @author wangchaocheng
 * @date 2025/03/14
 */
@Slf4j
@Component
public class SpringContextHolder implements ApplicationContextAware, DisposableBean {

    private static ApplicationContext applicationContext = null;

    /**
     * 从静态变量applicationContext中取得Bean, 自动转型为所赋值对象的类型.
     */
    @SuppressWarnings("unchecked")
    public static <T> T getBean(String name) {
        assertContextInjected();
        return (T) applicationContext.getBean(name);
    }

    /**
     * 从静态变量applicationContext中取得Bean, 自动转型为所赋值对象的类型.
     */
    public static <T> T getBean(Class<T> requiredType) {
        assertContextInjected();
        return applicationContext.getBean(requiredType);
    }

    /**
     * 检查ApplicationContext不为空.
     */
    private static void assertContextInjected() {
        if (applicationContext == null) {
            throw new IllegalStateException("applicationContext 属性未注入, 请在 applicationContext.xml 中定义 SpringContextHolder 或在 SpringBoot 启动类中注册 SpringContextHolder");
        }
    }

    /**
     * 清除SpringContextHolder中的ApplicationContext为Null.
     */
    private static void clearHolder() {
        log.debug("清除 SpringContextHolder 中的 ApplicationContext: {}", applicationContext);
        applicationContext = null;
    }

    @Override
    public void destroy() {
        SpringContextHolder.clearHolder();
    }

    @Override
    public void setApplicationContext(@NotNull ApplicationContext applicationContext) throws BeansException {
        if (SpringContextHolder.applicationContext != null) {
            log.warn("SpringContextHolder 中的 ApplicationContext 被覆盖, 原有 ApplicationContext 为: {}", SpringContextHolder.applicationContext);
        }
        SpringContextHolder.applicationContext = applicationContext;
    }
}
